Polygon aquarium



FIG. 1 is a perspective view of the polygon aquarium;

FIG. 2 is a front view of the polygon aquarium;

FIG. 3 is a side view of the polygon aquarium;

FIG. 4 is a top view of the polygon aquarium; and,

FIG. 5 is a bottom view of the polygon aquarium.

The ornamental design for a polygon aquarium, as shown, and described.